Birthstone Lists http://www.bernardine.com/birthstone/modern.htm
All About Birthstones - History http://lovejoyjewelry.com/all_about_birthstones.htm
The Rainbow of Gems http://www.tradeshop.com/gems/rainbow.html
birthstones - facts, history, folklore http://www.bernardine.com/gemstones/index.htm
The Mineral and Gemstone Kingdom http://www.minerals.net/
Common Minerals and Their Uses http://www.mii.org/commonminerals.html